A141974 - OEIS

%I #11 Sep 08 2022 08:45:35

%S 23,79,107,163,191,331,359,443,499,751,863,919,947,1031,1087,1171,

%T 1283,1367,1423,1451,1619,1759,1787,1871,2011,2039,2179,2207,2347,

%U 2459,2543,2683,2711,2767,2851,2879,2963,3019,3187,3271,3299,3467,3607,3691,3719

%N Primes congruent to 23 mod 28.

%H Vincenzo Librandi, <a href="/A141974/b141974.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 12n log n. - _Charles R Greathouse IV_, Jul 02 2016

%t Select[Prime[Range[1500]],MemberQ[{23},Mod[#,28]]&] (* _Vincenzo Librandi_, Aug 17 2012 *)

%t Select[Range[23,4000,28],PrimeQ] (* _Harvey P. Dale_, Nov 24 2017 *)

%o (Magma) [p: p in PrimesUpTo(5000) | p mod 28 eq 23 ]; // _Vincenzo Librandi_, Aug 17 2012

%o (PARI) is(n)=isprime(n) && n%28==23 \\ _Charles R Greathouse IV_, Jul 02 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jul 11 2008